TRH has a widespread distribution throughout the CNS consistent with a role in neuronal function in addition to regulation of pituitary hormone secretion. Indeed, much evidence from recent neurobiologic studies in man and other animals suggests that this substance is a neurotransmitter or neuromodulator in the mammalian CNS with potential biomedical implication. The purpose of this conference is to coalesce the knowledge derived from the remarkable advance in a number of different areas that have taken place during the past five years in the biomedical role of this tripeptide amide. It has been established that TRH is the product of ribosomal and not enzymatic biosynthesis and that the TRH precursor itself is the progenitor of a whole new family of peptides in addition to TRH. Further, important advances have been made in understanding the factors regulating the binding of TRH and its analogs to receptors. The effects of TRH on inositol second messenger systems in the pituitary provide a neurochemical model for the wide range of CNS action attributed to this peptide. TRH is co-localized in brain stem neurons with another neural peptide, substance P, and a classical neurotransmitter, 5 hydroxytryptamine, and it is now recognized that the secretion of all these substances may be intimately related. Finally, there have been important clinical studies pointing to a possible therapeutic role for TRH in amyotrophic lateral sclerosis (ALS), spinal trauma, and cardiovascular shock. This proposed conference sponsored by the New York Academy of Sciences will attract scientists form a wide range of disciplines, each involved in different aspects of TRH biology. As a forum, it will bring together investigators form diverse backgrounds including molecular biology, neuroendocrinology, pharmacology, peptide chemistry, neurobiology, neurochemistry, enzymology, and clinical neurology. This conference will provide a means of integrating new information on TRH in a multidisciplinary fashion, identifying specific areas of neurobiology requiring further study and fostering collaborative studies between scientists of separate disciplines.